Orbit Scenekit camera around specific node - swift

Question

I'm having a difficult time trying to figure out how to get my SceneKit camera to orbit around a specific node in my game.
If I have a single node (a ship) and a camera in my scene everything works fine. If I add an additional node (a planet) the cameras pivot point appears to change from my ship to a space between my ship and planet.
Things I've tried:
Setting a lookat constraint on my camera (set to the ship)
Settingcamera position to my ship (it will move but the pivot point
still seems to be between the two objects)
Changing the cameras pivot point
example:
class TestSceneViewController: UIViewController, SCNSceneRendererDelegate {
var scnView: SCNView = SCNView()
var scnScene: SCNScene!
var cameraNode: SCNNode!
var ship: SCNNode!
override func viewDidLoad() {
super.viewDidLoad()
setupView()
setupScene()
setupCamera()
...
func setupView() {
// scnView = self.view as! SCNView
// retrieve the SCNView
scnView = SCNView(frame: view.frame)
scnView.showsStatistics = true
view.addSubview(scnView)
scnView.allowsCameraControl = true
scnView.defaultCameraController.interactionMode = .orbitTurntable
scnView.defaultCameraController.inertiaEnabled = true
scnView.delegate = self
scnView.isPlaying = true
scnView.loops = true
}
func setupScene () {
scnScene = SCNScene()
scnView.scene = scnScene
let ships = SCNScene(named: "art.scnassets/simpleshuttle3.scn")
ship = ships!.rootNode.childNode(withName: "ship", recursively: true)
ship?.position = SCNVector3(x: 0, y: 0, z: 0)
scnScene.rootNode.addChildNode(ship!)
let planets = SCNScene(named: "art.scnassets/sphere.scn")!
if let planet = planets.rootNode.childNode(withName: "Ball", recursively: true){
planet.position = SCNVector3(x: 0, y: 0, z: 40)
scnScene.rootNode.addChildNode(planet)
}
}
func setupCamera() {
cameraNode = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.position = SCNVector3(x: ship.position.x, y: ship.position.y, z: 80)
cameraNode.camera?.motionBlurIntensity = 1.0
cameraNode.camera?.automaticallyAdjustsZRange = true
scnScene.rootNode.addChildNode(cameraNode)
}

Answer 1

You are enabling the manual camera control.
scnView.allowsCameraControl = true
If you want to use e.g. SCNLookAtConstraint you have to disable that. Otherwise you have a conflict. The camera is not supposed to point at a certain position while simultaneously being rotated by the user.
If you want to stay with the default camera controller you can create an additional SCNNode as the parent for your planet and the ships. This parent node can now be moved so that the pivot point is at your desired position.